高温快速固相烧结合成Zr_(1-x)Hf_xW_2O_8的Raman光谱研究

Raman Spectroscopic Study of Zr_(1-x)Hf_xW_2O_8 by Fast Solid State Reaction

首次采用高温快速固相烧结的方法合成了Zr1-xHfxW2O8(x=0,0.2,0.3,0.4,0.5,0.6,1)固溶体。合适的合成条件为:温度1573~1693 K,时间10 min^1 h,该方法使合成时间和能耗比传统固相反应烧结显著降低。Zr1-xHfxW2O8的晶胞参数与晶胞体积随Hf4+含量的增加而减小。合成的样品晶粒尺寸比常规固相烧结合成样品的颗粒尺寸较小,颗粒大小在1~10μm之间。拉曼光谱分析表明,Zr1-xHfxW2O8(0<x<1)拉曼谱峰的数目与α-ZrW2O8和α-HfW2O8相同,各拉曼模的位置介于二者对应模位置之间,随着Hf4+离子替代Zr4+离子数的增大,Zr1-xHfxW2O8(0<x<1)中多面体的内振动模向高频方向移动,而外模则向低波数移动,逐渐接近α-HfW2O8的拉曼峰位置。这些结果预示着Zr1-xHfxW2O8(0<x<1)的性质介于α-ZrW2O8和α-HfW2O8之间。

Zr1-xHfxWzO8（x=0,0. 2,0.3,0.4,0.5,0. 6,1）samples are successfully synthesized by fast solid state reaction for the first time. The appropriate temperature and sintering time are 1573-1693 K and 10-60 min. respectively. This approach reduces greatly the sintering time and energy waste. The grain sizes are between 1-10μm, smaller than those by conventional solid state reaction. The crystal cell parameters and volume decrease with the contents of Hf^4＋. Raman spectroscopic study shows that the number of modes in Zr1-xHfxW2O8 is the same as that in α-ZrW2O8 and α-HfWzOs, but each mode position is between its corresponding mode positions of them; The internal vibrational modes shift to higher while the external modes shift to lower frequencies, and both gradually approach the mode positions of α-HfW2O8 with the contents of Hf^4＋. The results suggest that the properties of Zr1-xHfxW2O8 （0〈x〈1） should be similar to and between α-ZrW2O8 and α - HfW2O8.